In a process of manufacturing, for example, a semiconductor device, the diameter of a substrate to be processed such as a silicon wafer or a compound semiconductor wafer has recently been increased, and also, the thickness of the substrate to be processed has recently been decreased. When a thin substrate to be processed with a large diameter is conveyed or polished, warpage or crack may occur. Accordingly, the substrate to be processed is bonded to a supporting substrate such as, for example, a glass substrate, so as to reinforce the substrate to be processed.
Bonding of the substrate to be processed and the supporting substrate is performed by using a bonding device. In the bonding device, the supporting substrate and the substrate to be processed are held by, for example, an upper chuck and a lower chuck, respectively, and then are pressed by moving the upper chuck or the lower chuck. See, e.g., Japanese Laid-Open Patent Publication No. 2012-69900. An adhesive is applied on the surface of the substrate to be processed or the supporting substrate, and thus the substrate to be processed and the supporting substrate are pressed as described above to be bonded with each other.
Also, Japanese Laid-Open Patent Publication No. 2012-69900 discloses a bonding system, in which, besides the bonding device, for example, a conveyance device for conveying a substrate to be processed or a supporting substrate, a coating device for coating an adhesive to the substrate to be processed, and a heating device for heating the substrate to be processed coated with the adhesive are integrally incorporated.